The present invention relates to sprays designed to deliver active ingredients, such as insecticides, fragrancers and cleaners. More particularly it relates to aerosol sprays that contain limonene (for orange fragrance and solvent purposes) as well as additional chemicals to minimize can corrosion and discoloration during storage.
A variety of sprays are known. For example, U.S. Pat. No. 5,773,016 describes aerosol emulsion sprays formed from water, hydrocarbon solvent, surfactant, insecticide(s), and hydrocarbon gas propellant(s). This patent also describes the desirability of adding sodium nitrite, sodium benzoate, or mixtures thereof to reduce can corrosion during storage.
U.S. Pat. No. 5,792,465 described relatively stable microemulsions used to deliver insect control agents, as well as the possibility of adding propane/isobutane mixtures as a preferred propellant. This patent also noted that d-limonene (an element of orange oil) could be added as well, as a solvent.
In separate work it has been suggested to add butylhydroxytoluene (“BHT”) to some insecticidal mixtures, primarily for its antioxidant properties (to protect actives).
While the art has therefore suggested the use of limonene in certain sprays, such formulations tend to quickly discolor, particularly in the presence of the anti-corrosive agent sodium nitrite. This can make a consumer less willing to use such a spray in the home, even though orange fragrance is highly desirable.
Hence, a need exists for improved spray formulations containing limonene.